How to Backup Outlook OST Files

Updated on March 07, 2025 by Nasir Khan

Business email data is very important for any organization, but what if your critical data get lost for some reason; no one wants to get trapped in such a situation. One must have a backup of their data files. So, in this page we will discuss how to backup Microsoft Outlook OST file with manual and professional ways.

As a business owner or member of an organization, you must understand the importance of Outlook emails. You could face significant consequences if you lose your company email data file for any reason. It also applies to personal users. People use Exchange Server to centrally handle, distribute, and store business emails in enterprises and organizations. It also includes many tools for storing and sharing contacts, schedules, tasks, and other data files. Microsoft Outlook, the most common email client, can work with Microsoft Exchange Server. Once you set up the Exchange Server as a profile within Microsoft Outlook, you can enable the Outlook offline feature to send and receive emails through the server. As a result, you don't need to use two different programs to manage your business emails, contacts, and other data files.

If you are using Microsoft Outlook with Exchange Server, then you must be familiar with cached Exchange mode. When you configure MS Outlook with Exchange, there is an option- Cached Exchange mode, and by enabling this option, Microsoft Outlook will download a copy of your mailbox data to your local computer. This is called an OST file, also known as an Offline Storage Table, a type of Outlook data file. Being an offline folder file, OST allows you to access your Exchange mailbox data even if you are not connected to the internet. And once the connection gets re-established, you can synchronize the changes you made earlier during the offline mode.

What is Microsoft Outlook OST File?

Microsoft Outlook creates OST (Offline Storage Table) files to let users access emails, contacts, calendars, and tasks offline. These files store a local copy of your mailbox data. When you're online, Outlook syncs the changes made in the OST file with your Exchange or Office 365 account.

Since OST files are linked to a specific user profile, it's important to back them up to avoid losing data in case of corruption or accidental deletion. This is especially important when dealing with large or critical email data.

What is the Need to Backup Outlook OST file?

There are many reasons why we need backup OST files; some of the common reasons are given below:-

OST Synchronization Problem:- In the offline mode, a user can work with OST files. When it comes to Exchange Server, it is not possible. As a result, working on the file becomes problematic when Outlook is synchronized with the Exchange Server. As a result, a backup of the OST file in Outlook is required.

Authentication Issue:- To access the data on Exchange Server, proper credentials along with validation are required. To avoid all the complex procedures, it is better to keep an archive of the OST file in Outlook 2013.

Data Recovery: - In case your OST file got deleted, corrupted, damaged due to some reasons then you cannot access your OST file. To make data available, it is recommended to back up the offline .ost files for the accounts.

OST Corruption:- Due to virus attacks, abrupt shutdown and other software related issues, the OST file becomes inaccessible and its data cannot be availed. So, to rely on the OST file is a mistake. Hence it is necessary to back up OST file data of Outlook 2019, 2016, 2013, and 2010 & Exchange OST files.

Local Storage Advantages:- Having data in the local storage favors user in all conditions. There might be some cases where you cannot access the server or away from your system or any unexpected circumstances. Having data in portable devices allows you to access data even during downtime or connectivity.

Now, we are going to explain to you the step-by-step process of manual OST File Conversion and a Professional tool. However, it is like walking on the eggshell to complete the operation using a manual method. In that case, you can seek the help of the automated solution we discussed below to backup Outlook OST file to PST and other many file format.

Manual Methods to Backup Microsoft Outlook OST file:

Method 1: Use Copy/Paste Feature to Backup OST Files to External Drive

This is the simplest and most basic way to backup your OST files by copying the file to a safe location. Here's how:

Locate Your OST File:

Open File Explorer and navigate to the folder where your OST files are stored. Typically, these files are located in:

C:\Users\ \AppData\Local\Microsoft\Outlook\

If you can't find the folder, you may need to enable hidden files and folders in File Explorer.

Copy the OST File:

Once you’ve found the OST file (it may have a name similar to Outlook.ost), simply right-click on it and select Copy.

Paste the Backup in a Safe Location:

Choose a secure location for your backup. This could be an external hard drive, USB flash drive, or cloud storage folder. Paste the copied OST file into the backup location.

Method 2: Use Import/Export Feature to Save Outlook OST file to PST format

1. Launch and open Microsoft Outlook and click on the File tab.
2. Now, go to the option Open & Export and click Import /Export.
   
3. In the next window on the screen, select Export to a file option and click on the Next tab.
   
4. Now, select the Outlook data file (.pst) option in the next window and click the next tab.
   
5. You need to check the folders you want to back up or the Include subfolders to create the entire OST backup and click the Next button.
   
6. Click Browse and then navigate to your preferred save location. Enter your backup file's identifying name, and click OK
7. Now, select do not export duplicate items to avoid duplicates before clicking Finish.
   

Method 3: Use Archive Feature to Backup OST to PST file

Archiving is not precisely backing up the OST file; it is more like moving your important data onto a separate folder in Outlook. Remember, archiving doesn't backup Outlook contacts, know how to backup and move Outlook Contacts here.

You can follow these set of instruction given below to archive Outlook:

1. Open Microsoft Outlook on your local system and click on the File tab.
2. Now, click Tools (or Cleanup Tools for Older Outlook versions).
   
3. A screen will open up on the screen. Select Set Archive Folders (Archive for Outlook 2016 and previous versions).
4. In the Setup Archive Window, Browse the destination location where the archived PST file will be saved.
   
5. Finally, click the OK button to finish the Outlook archiving process.

Method 4: Backup OST file to Cloud Server

Cloud-based backup solutions are increasingly popular due to their ease of use and reliability. Services like Google Drive, OneDrive, or Dropbox can automatically back up your Outlook OST files, ensuring your data is always accessible from any device.

Choose a Cloud Storage Service:

If you don’t already have one, choose a cloud storage service like OneDrive or Google Drive. These services offer sufficient storage space for OST file backups.

Upload Your OST File:

After manually copying the OST file (following Method 1), upload it to your cloud storage. Most services offer desktop applications that allow you to sync files automatically.

Set Up Automatic Backups:

Enable automatic syncing in your cloud storage app to ensure your OST files are regularly backed up.

Access Your Backup Anytime:

With cloud backup, your OST file is available from anywhere with an internet connection.

As described, above methods are helpful for backup Outlook OST files. However, there are certain limitations to these methods:

Limitations of manual methods:

• These manual methods are more time-consuming and have a tedious backup process. It is unsuitable if you are hurrying to have data in the desired format.
• Manual methods require high technical expertise to handle the complete backup task. A non-technical user usually needs help with following the manual steps.
• While using the manual method to backup Outlook OST file to PST involves a high risk of data loss during the process. There are high chances of human error.
• It would help if you used the same computer on which the OST file was created. If you are using another new computer, you cannot use manual methods.
• A virus or malicious software attack can corrupt multiple OST files that cannot be repaired using manual methods, resulting in inaccessible OST files.
• If an email or other email component, such as Contact, is accidentally deleted, the archiving method and the export/import wizard do not restore the deleted email or other component.
• The manual method is size bounded. You can only process small-sized OST files.

Professional Way to Backup Outlook OST to PST file and other formats:

If you have faced these limitations, you cannot Backup Outlook OST file to PST using manual methods. However, we have an automated solution to overcome these limitations: an OST converter tool can back up Outlook OST file to PST within a few clicks. This professional utility is Regain OST to PST Converter Software. It has multiple user-oriented advanced features that make conversion efficient. Some of the prominent features of this professional utility are described below:

• There is no limit on adding and converting multiple OST files in a single go. Users can efficiently execute batch backups of OST data.
• Efficiently recover corrupt OST files and takes the backup of deleted emails and other mail components.
• Other than PST file format, it also offers multiple other formats in which you take backup OST files. E.g., MBOX, EML, MSG, ICF, PDF, ICS, and TGZ.
• The tool professionally converts and backup Outlook OST into PST and keeps OST data formatting and data hierarchy intact.
• Resolve Synchronization errors and other Outlook-related errors.
• Display the preview of selected OST files emails before the actual backup. It helps users to get ensure the correctness of the data.
• With Regain OST to PST Converter, users can import OST backup files to Office 365 or Exchange Server Platform. It is icing on the cake if you are an Office 365/Exchange Server user.
• Users can also set the size for the resultant PST files. The tool offers an option to split the resultant PST files. You can easily set the size limit, and the tool will automatically split the file upon reaching the limit. Keeping the size of the PST file small reduces the risk of PST file corruption.

Backup Outlook OST file using Regain OST Converter tool

• Step 1: Install and run Regain OST to PST Converter software on your system. Click the 'Add file' option to upload OST data files on the tool's panel.
  
• Step 2: The tool will automatically pick the default location of OST files and load it on the software's panel. Click the scan option.
  
• Step 3: Now, check the desired folder from the listed folders and click the Next button.
  
• Step 4: Choose the desired file saving option in which you want to back up OST file data. And also, enter the file destination where you want to save the data on your local system after backup.
  
• Step 5: The software also provides an option to easily back up Outlook OST files in Office 365 & Live Exchange Server platform. You need to enter your User ID and Password and click Connect tab given below.
  
• Once the backup process is completed, the tool will give the completion message, as shown in the screenshot below.

Know How to Backup Outlook OST to PST file Working Video – Watch Now!

Final Words:

There are many reasons to backup Outlook OST file to PST file format, and the reason varies from person to person. But, one thing is common in all: its advantages for users. In this write-up, we have discussed both manual and professional methods for the users. The manual method comes free of cost but has limitations and disadvantages. On the other hand, a professional tool developed by Regain Software offers fast and efficient processing. Users get multiple highly advanced features and options. The GUI of the tool is straightforward to understand, and one can easily backup Outlook OST file into PST file. To ensure users about the software, a free demo version of the tool is also available to download. The trial version allows to process of 30 items per folder; you must install and try it.

Frequently Asked Questions

Q 1. If I purchase the license for Regain OST Converter, will I get any technical support if I need?

Ans. Yes. You will get round-the-clock technical support if you need any technical support related to the Regain OST to PST Converter Software. You can contact us by leaving a message on the chat box or email us at support@regainsoftware.com or sales@regainsoftware.com. A telephone number is also given on the contact page for telephonic assistance.

Q 2. How many files can I add in a batch to backup Outlook OST file to PST file format?

Ans. There is no limitation on the number of OST files or the size of the OST files. You can add multiple .ost files for batch conversion.

Q 3. Will this utility be compatible with Windows 7, as I am still using it?

Ans. Regain OST to PST Converter Software is compatible with all versions of the Windows operating system. If you are using Windows 7 or any other version, then there is no need to worry about compatibility; you can easily use this utility.

Q 4. What will happen to the OST files that are corrupted or inaccessible for any reason?

Ans. This software is developed with highly advanced algorithms; hence, it can handle corrupt OST files. This software repairs and then converts OST to PST file format if there is any corruption issue with the .ost files. You quickly add and convert OST to PST without any issue with corrupt OST files.

Q 5. How different is this free demo version from the licensed version?

Ans. The free demo version is just a restricted version of the licensed version. With the licensed version, there is no limitation when backup Outlook OST to PST file format, while there is a limitation of 30 items per folder with the demo version. You can easily download and use the free demo version, and after getting satisfied with the tool's working, you can easily upgrade the demo version to the full version.

Q 6. Will I get the same folder hierarchy after backup Outlook OST to PST file format?

Ans. Yes. After converting OST to PST file format, you will get the same folder hierarchy. It helps users to handle the data as they get the same hierarchy with which they are familiar.

Q 7. Is it Possible to directly backup OST files in Outlook?

Ans. No, Outlook doesn’t have a built-in tool for backing up OST files directly. You’ll need to use third-party tool like Regain OST File Converter to export Offline OST data to PST file.

Q 8. Is it safe to store OST backups on the cloud Server?

Ans. Yes, storing OST files on the cloud is safe and reliable, as long as you use a trusted cloud storage service. It keeps your data accessible from anywhere and protected with encryption.